1000,000 per timing belt?
Hmmm---
Buddy of mine has a Subie, and he told me that he changes ( or tries to)
every 45, to 50,000 as per factory recommendation.
My Flat four Honda Goldwing requires the same service at about the same
interval.
I don't think I would want to go that long without doing this type of
service.
Smacking valves doesn't sound appealing!! :>(

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Terry 85 GL